### Related Formula Faraday's law of electrolysis equation: textMoles of electrons (equivalents) = fracI cdot tF$\text{Moles of electrons (equivalents)} = \frac{I \cdot t}{F}$ Water ion product relation: textpH + textpOH = 14$\text{pH} + \text{pOH} = 14$ ### Core Logic During the electrolysis of brine (NaCl(aq)$NaCl(aq)$), hydroxide ions (OH^-$OH^-$) are generated at the cathode: 2H_2O + 2e^- rightarrow H_2 + 2OH^-$2H_2O + 2e^- \rightarrow H_2 + 2OH^-$ Given metrics: - Final textpH = 12 implies textpOH = 14 - 12 = 2$\text{pH} = 12 \implies \text{pOH} = 14 - 12 = 2$ - [OH^-] = 10^-2mathrm\ M$[OH^-] = 10^{-2}\mathrm{\ M}$ - textVolume = 600mathrm\ mL = 0.6mathrm\ L$\text{Volume} = 600\mathrm{\ mL} = 0.6\mathrm{\ L}$ - textTime = 5mathrm\ min = 300mathrm\ s$\text{Time} = 5\mathrm{\ \min} = 300\mathrm{\ s}$ ### Step 1: Calculate Moles of Hydroxide Produced Find the absolute moles of OH^-$OH^-$ ions generated: textMoles = textMolarity times textVolume (L) = 10^-2 times 0.6 = 6 times 10^-3text moles$\text{Moles} = \text{Molarity} \times \text{Volume (L)} = 10^{-2} \times 0.6 = 6 \times 10^{-3}\text{ moles}$ ### Step 2: Relate to Electrical Current Since 1$1$ mole of electrons produces 1$1$ mole of OH^-$OH^-$, the moles of charge equals 6 times 10^-3$6 \times 10^{-3}$. Applying Faraday's equation: 6 times 10^-3 = fracI times 30096500$6 \times 10^{-3} = \frac{I \times 300}{96500}$ I = frac6 times 10^-3 times 96500300 = 1.93mathrm\ A$I = \frac{6 \times 10^{-3} \times 96500}{300} = 1.93\mathrm{\ A}$ Rounding to the nearest integer gives 2$2$. ### Pattern Recognition Always convert a given textpH$\text{pH}$ value into [OH^-]$[OH^-]$ concentration when dealing with cathodic water reduction. Tracking the relationship where 1\ e^- equiv 1\ OH^-$1\ e^- \equiv 1\ OH^-$ provides a direct shortcut to link textpH$\text{pH}$ changes to current flow. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Chemistry: Electrochemistry

### Related Formula textOxidising Capacity propto textStandard Reduction Potential (E^ominus)$\text{Oxidising Capacity} \propto \text{Standard Reduction Potential } (E^{\ominus})$ ### Core Logic A higher positive value of standard reduction potential (E^ominus$E^{\ominus}$) indicates a stronger tendency to undergo reduction, hence behaving as a stronger oxidising agent. Comparing the given values: * mathrmE_mathrmSn^4+/mathrmSn^2+^ominus = +1.15mathrmV$\mathrm{E}_{\mathrm{Sn}^{4+}/\mathrm{Sn}^{2+}}^{\ominus} = +1.15\mathrm{V}$ * mathrmE_mathrmTl^3+/mathrmTl^ominus = +1.26mathrmV$\mathrm{E}_{\mathrm{T}l^{3+}/\mathrm{T}l}^{\ominus} = +1.26\mathrm{V}$ * mathrmE_mathrmAl^3+/mathrmAl^ominus = -1.66mathrmV$\mathrm{E}_{\mathrm{Al}^{3+}/\mathrm{Al}}^{\ominus} = -1.66\mathrm{V}$ * mathrmE_mathrmPb^4+/mathrmPb^2+^ominus = +1.67mathrmV$\mathrm{E}_{\mathrm{Pb}^{4+}/\mathrm{Pb}^{2+}}^{\ominus} = +1.67\mathrm{V}$ Since +1.67mathrmV$+1.67\mathrm{V}$ is the highest value, mathrmPb^4+$\mathrm{Pb}^{4+}$ possesses the strongest oxidising capacity[cite: 745, 746]. ### Pattern Recognition Strongest oxidising agent = Most positive reduction potential. Weakest oxidising agent = Most negative reduction potential. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Chemistry: Electrochemistry Class 12 Chemistry: p-Block Elements

### Related Formula For weak electrolytes, the degree of dissociation alpha$\alpha$ increases sharply near infinite dilution according to Ostwald's Dilution Law: alpha = sqrtfracK_aC$\alpha = \sqrt{\frac{K_a}{C}}$ ### Core Logic When a weak electrolyte is diluted (concentration C ightarrow 0$C ightarrow 0$), its molar conductivity increases steeply. Conversely, when plotted against sqrtC$\sqrt{C}$, as concentration increases, the degree of dissociation drops rapidly, causing a sharp decrease in molar conductivity[cite: 188, 204]. This matches the curve given below:

### Pattern Recognition Weak electrolyte plots feature a steep asymptotic exponential-like rise towards the y-axis as C ightarrow 0$C ightarrow 0$, meaning a sharp decrease occurs with increasing concentration[cite: 204, 752]. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Chemistry: Electrochemistry